Keywords and Identifiers in Python

 Keywords and Identifiers in Python

Keywords and identifiers are fundamental concepts in Python, as well as in many other programming languages. They play crucial roles in defining and structuring Python code.

Keywords:

   Keywords are reserved words in Python that have predefined meanings and cannot be used as identifiers (variable names, function names, etc.). They are an integral part of the Python language and serve specific purposes. There are 35 such keywords in python. Here are some examples of Python keywords.

False                None                True            And             as

Assert             Async              Await         Break     class

Continue     Def      Del Elif     else

Except             Finally               For             From            global

If                       Import               In               Is                  lambda

Nonlocal            Not                   Or              Pass            raise

Return               Try                    While        With              yield

Please note that the number and specific keywords may change with newer Python versions, so it's always a good idea to check the documentation or use Python's keyword module to obtain the current list for your Python version.

   Attempting to use these words as variable names will result in a syntax error.

Identifiers:

   Identifiers are user defined names used for various programming elements like variables, functions, classes, etc. Python identifiers have certain rules and conventions:

    1. They must start with a letter (az, AZ) or an underscore (_).

    2. The rest of the identifier can contain letters, digits (09), and underscores.

    3. Identifiers are case sensitive, meaning myvar and myVar are treated as different identifiers.

    4. They cannot be a Python keyword. Using a keyword as an identifier will result in a syntax error.

    5. They should follow naming conventions for better code readability. For instance, variable names are typically in lowercase with words separated by underscores (snake_case), while class names are typically in CamelCase.

   Examples of valid identifiers:

    My_variable     _private_var     CamelCaseIdentifier temp_5

   Examples of invalid identifiers (due to starting with a digit or containing a special character):

    123var

    my.var

In summary, keywords are reserved words with predefined meanings in Python, while identifiers are user defined names for variables, functions, classes, etc., that follow certain rules and conventions. It's important to choose meaningful and descriptive identifiers in your code to enhance readability and maintainability.